upstream commit
avoid BIGNUM in KRL code by using a simple bitmap;
feedback and ok markus
diff --git a/sshbuf-getput-basic.c b/sshbuf-getput-basic.c
index 06d6cc4..8ff8a0a 100644
--- a/sshbuf-getput-basic.c
+++ b/sshbuf-getput-basic.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshbuf-getput-basic.c,v 1.3 2015/01/12 15:18:07 djm Exp $ */
+/* $OpenBSD: sshbuf-getput-basic.c,v 1.4 2015/01/14 15:02:39 djm Exp $ */
/*
* Copyright (c) 2011 Damien Miller
*
@@ -424,3 +424,39 @@
memcpy(d + 4 + prepend, s, len);
return 0;
}
+
+int
+sshbuf_get_bignum2_bytes_direct(struct sshbuf *buf,
+ const u_char **valp, size_t *lenp)
+{
+ const u_char *d;
+ size_t len, olen;
+ int r;
+
+ if ((r = sshbuf_peek_string_direct(buf, &d, &olen)) < 0)
+ return r;
+ len = olen;
+ /* Refuse negative (MSB set) bignums */
+ if ((len != 0 && (*d & 0x80) != 0))
+ return SSH_ERR_BIGNUM_IS_NEGATIVE;
+ /* Refuse overlong bignums, allow prepended \0 to avoid MSB set */
+ if (len > SSHBUF_MAX_BIGNUM + 1 ||
+ (len == SSHBUF_MAX_BIGNUM + 1 && *d != 0))
+ return SSH_ERR_BIGNUM_TOO_LARGE;
+ /* Trim leading zeros */
+ while (len > 0 && *d == 0x00) {
+ d++;
+ len--;
+ }
+ if (valp != 0)
+ *valp = d;
+ if (lenp != NULL)
+ *lenp = len;
+ if (sshbuf_consume(buf, olen + 4) != 0) {
+ /* Shouldn't happen */
+ SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR"));
+ SSHBUF_ABORT();
+ return SSH_ERR_INTERNAL_ERROR;
+ }
+ return 0;
+}